Automatic electric switch



June 23, 1925. 1,542,931

E. B. FOOTE AUTOMATIC ELECTRIC SWITCH Filed April 21. 1923 Patented June23, 1925.

UNITED STATES 1,542,931 PATENT OFFICE.

EDWARD B. FOOTE, OF ROCHESTER, NEW YORK, ASSIGNOB TO TAYLOR INSTRUMENTCOMPANIES, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC ELECTRIC SWITCH.

Application filed April 21, 1923. Serial-No. 633,767.

To all whom it may concern:

Be it known that I, EDWARD B. Foo'rn, a citizen of the United States,residing at Rochester in the county of Monroe and State of ew York, haveinvented certain new and useful Improvements in Automatic ElectricSwitches; and I do hereby declare the following to be a full, clear, andexact descriptionof the same, reference being had to the accompanyingdrawings, forming part of this specification, and to the referencenumerals marked thereon.

This invention relates to automatic electric switches of the varietyadapted to be operated by fluid pressure, from a distant station if sodesired, for opening or closing a switch controlling an electriccircuit, the chief object ofthe invention being to provide a simple,practical and eflicient device of this character adapted to beselectively arranged for operation by fluid pressure to either open orclose a controlled circuit.

In the drawings:

Figure 1 is a central sectional view through device of the classdescribed embodying the present invention, and showing the same arrangedfor closing a circuit, an

Figure 2 is a similar view but showing the parts arranged for openingthe controlled circuit.

Similar reference numerals throughout the several views indicate thesame parts.

The invention is disclosed in the present instance, by way ofillustration, as embodied in a form of construction and arrangementwhich has been found practical and efficient in actual use, comprisingpreferably a casing 5 formed with-a cylindrical bore 6 which serves as apressure containing cylinder to which the operating fluid pressure, asfor example compressed air, is admitted adjacent its opposite endsthrough ports 7 or 8 depending upon whether the device is to be used toclose or open the controlled circuit, as hereinafter explained. Slidingwithin the cylinder in pressure tight relation with the walls thereof isa piston or plunger 9 preferably having a reduced end 10 adapted toengage the adjacent cylinder end as a stop for limiting the movement ofthe piston in that direction. The ends of the piston are furthermorepreferably formed with peripheral depressions or seats 11 in which maybe seated one end of a coiled spring 12 of a diameter adapted to fitloosely within the cylinder walls with the opposite end of the springabutting the. corresponding cylinder "end. This spring may beselectively located in either end of the cylinder for urging the pistonin opposite directions against fluid pressure applied through one of theports 7 or 8, to operate switch means located at one end of the cylinderas more fully explained hereafter.

In the arrangement shown in Fi re 1 fluid pressure is admitted to theleft hand end of the cylinder through a pipe 13, while port 8communicatin with the opposite end of the cylinder is so stantiallyclosed by a removable screw plug 14 having however a small vent aperture15. It is apparent from this construction that spring 12 tends tomaintain piston 9 at the left hand end of the cylinder as shown, and theadmission of fluid pressure through pipe 13 moves the piston toward theright against spring 12 for operating the switch means in the right handend of the cylinder hereafter described. In the arrangement of the abovearts shown in Figure 2, however, spring 12 is placed in the left handend of the cylinder and pipe 13 and plug 14 reversed in application tothe cylinder ports so that the admission of pressure through pipe 13tends to move the piston in the opposite direction against the pressureof the spring.

The switch parts comprise preferably a plug 16 provided with leads 17for connection in a circuit to be controlled as indicateddiagrammatically at 17 and having a threaded end 18' adapted to bescrewed into the bore of a coupling sleeve 19 externally threaded as at20 for engagement with the internally threaded end of the pressurecyllnder. The plug carries spaced insulated contacts 21 connected withthe respective leads 17. The iston 9 at this end is centrally cored andtted with an insulated sleeve 22 in which is carried a post 23 havingmounted on its end exteriorly of the piston a switch contact 24 adaptedto bridge and connect contacts 21 when the piston is moved toward theright, the switch being shown in open position in Figure 1, and inclosed position in Figure 2.

In operation the switch connections 17 are applied to the circuit to becontrolled which may be of any variety. If the circuit is one which isnormally open and it is desired to utilize the device for closing thiscircuit the parts are arranged as shown in Figure 1 with the pressureconnection applied to the left hand port '2'. In this arrangement theapplication of fluid pressure from a suitable source of supply (notshown) serves to move the piston toward the right against the oppositionof the spring and to close the switch contact. If, on the other hand,the circuit is a normally closed one which it is desired to open b 7means of the device, then the connecting s eeve 19 is unscrewed with theplug 16 and the spring 12 and the piston removed, the spring beingreinserted in the cylinder at its lefthand end and the piston sleeve andplug replaced as shown in Figure 2. In this arrangement the pressure isappiied through pipe 13 and the right hand port 8, the left hand portbeing closed by means of the plug 14. The admission of the fluidpressure then serves to move the piston toward the left, the confinedair escaping through vent 15 of plug 14. The switch is thus openedagainst the force of the spring which tends to close it again when thepressure is removed.

As apparent from the above description and drawing, the device comprisesbut few parts of simple form which may be manufactured at a low cost andare of a durable nature capable of reliable operation over a long periodof time. The parts may be quickly and easily disposed in either of thearrangements shown in Figures 1 and 2 for using the apparatusselectively to either open or close the circuit as may be desired inaccordance with particular installations.

I claim as my invention:

1. In a fluid pressure operated switch for controlling an electriccircuit, the combination of a cylinder, a piston therein, contactsadjacent one end of the cylinder, circuit control means adapted to bemoved by the piston for opening and closing a circuit through saidcontacts, means for admitting fluid pressuretoeither end of the piston,and yieldable means adapted to be assembled at either end of thecylinder 50 as to maintain the switch either in open or closed positionwhen the pressure of the fluid upon the piston is relieved.

2. In a fluid pressure operated switch, the combination of a pair ofswitch parts one of which is movable relatively to the other to open orclose the switch, a pressure container, a pressure actuated membermovable in said container and arranged to move said movable switch part,connections for applying fluid pressure to said member in either of twodirections,.and motive means adapted to be selectively assembled ateither end of said member to move it in either of said directions inopposition to said fluid pressure.

8. In a fluid pressure operated switch, the combination of switch partsmovable relatively to each other to either open or close the switch, apressure container, a pressure operated member movable in said containerand provided with means for effecting said relative movement of theswitch parts, connections for applying fluid pressure to said member ineither of two directions for effecting corresponding movements thereofto open and close the switch, respectively, and motive means adapted tobe selectively assembled in different positions for urging said memberin either of said directions in oposition to said fluid pressure.

at. In a fluid pressure operated switch, the combination of switch partshaving relative movements in either of two directions for opening andclosing the switch respectively, a pressure container, a pressureoperated member movable in either of two directions in said containerand provided with means for effecting said relative movements of theswitch parts, connections with a source of fluid pressure for applyingthe latter to said member selectively to effect either of said movementsthereof, and spring means adapted to be selectively assembled in eitherof two different positions within said container for urging said memberin either of said directions in opposition to said fluid pressure.

5. In a fluid pressure operated switch, the combination of switch partshaving relative movement in either of two directions for opening andclosing the switch respectively, a cylinder, a piston reciprocating insaid cylinder and provided with means for effecting said relativemovements of said switch parts, ports for selectively connecting saidcylinder on opposite sides of said piston with a source of fluidpressure for effecting said movements of the piston and switch parts,and a coiled spring adapted to be assembled on either side of saidpiston for urging the latter in one of said directions in opposition tosaid fluid pressure.

6. In a fluid pressure operated switch, the combination of a cylinder, apiston reciprocably mounted therein, cooperating contact means disposedin one end of the cylinder adapted to be opened and closed by thereciprocation of the piston, ports for connecting said cylinder onopposite sides of said iston with a source of fluid pres sure, and acoiled spring adapted to be as sembled in one end of the cylinder tonormally hold the contacts in closed position and also arranged to beassembled in the opposite end of the cylinder in a position to surroundthe contact means and to normally maintain it in open position.

EDIVARD B. FOOTE.

